Abstract: Based on the generalized theory of wide electron heam focusing, an aberration theory for wide electron beam focusing with curvilineal optical axis in electrostatic and magnetic imaging systems has ho studied using the rotational and non-orthogonal curvilineal coordinate systems. By defining the integration function, all aberration coefficients of the second-order geometrical aberration, the principal trajectory chromatic aberration and curvilineal paraxial trajectory chromatic aberration are given. The results of this paper have ho shown to be convenient for analysis and computer processing.